He was linked, how seriously I dont recall, when Merc ultimately chose to bring Schumacher out of retirement..... but yes he name was mentioned in relation to a lot of teams, including I seem to recall a long shot at a return to McLaren. But there is a lot of disparity between actual fact and what we read online!
Actually Toyota was another team he was supposedly offered a seat at to replace Glock. but knocked it back as he wanted a car capable of winning! And the money wasnt right. Not to mention they threw the towel in at the end of 2009..

* Mario Andretti joining Ferrari for 1978.
* Greg Moore and Dario Franchitti being closely looked at by McLaren for a drive in 1998. (Moore was also approached by Stewart at that time).
* Michael Andretti was highly touted for rides at Brabham in 1987, and at Ferrari, Williams, or March in 1989.
* Bobby Rahal was another name that popped up for the Brabham seat in '87.

One of the more interesting rumors I found: Alan Jones going to NASCAR in 1981.

The Greg Moore to F1 stuff definitely was around at the time. Mercedes were keen on funnelling him that way, but I seem to recall reading somewhere he was more keen on staying Stateside and most people reckon he would probably have ended up heading to NASCAR with Penske somewhere down the line.